Amazon Simple Storage Service (S3) is a low-cost & high-availability storage service provided by Amazon Web Services. It's very efficient and cheap, it allows you to store as much as you want and there is no limit, you pay for what you use and you pay as you go, there is no commitment. You can check their service details and pricing at http://aws.amazon.com/s3/

In this article we'll look at accessing the service using PHP library provided by Amazon.

Installing AWS PHP SDK

There are more than one way to install the SDK, you may use the one that suits you.
Download and install from http://aws.amazon.com/sdkforphp. You can get it from GitHub